It is sometimes desirable to separate particulates from a solution. It is well-known to use a centrifuge to separate particulates from a solution. As known in the art, a centrifuge is a device driven by a motor that rotates an object about a fixed axis, applying a centrifugal force perpendicular to the axis of rotation to separate an initial solution, or fluid product into discrete components.
Blood is a biological fluid product that can be characterized as a suspension of particles in a fluid. Blood primarily includes plasma, white wells, platelets, red blood cells, and other particulates present in different ratios and having different densities. When a blood sample is centrifuged, discrete layers are formed according to their densities. The least dense particulates will separate to form a top layer and the most dense particulates will separate and form a bottom layer. After blood is centrifuged a top layer is formed that is substantially plasma, a bottom layer is formed that is substantially red blood cells, and a middle layer is formed that is known in the art as a “buffy coat.” The buffy coat contains white blood cells and platelets with an amount of plasma and red blood cells. It is often desirable to isolate the buffy coat for various applications.
It is sometimes desirable to adjust the ratio of red blood cells present in the buffy coat. However, many prior art devices are configured such that adjusting the ratio of red blood cells in the buffy coat requires several steps and is cumbersome to achieve. Also, many prior art devices are configured such that particulate residue builds on the sidewalls over time, reducing optimization of a desired concentrate.
Therefore, a need exists to overcome the problems with the prior art as discussed above and that reduces residue build-up on the sidewalls, optimizes the concentrate of a desired layer(s), increases fluid exchange efficiency, and provides a more convenient device and method of adjusting ratios of particulates in a desired layer.